The United States endoscopy market size in 1999 was $3.6 Billion. Visualization products, which include rigid endoscopes, light sources and video accessories, represent a 17%, or more, segment of this market valued at more than $600 Million. According to Stryker Corporation's 1999 Fact Book, the world endoscopy market approaches $6 Billion, and the market for visualization products continues to grow at 8–10% per year.
Of the 5,000 hospitals in the U.S., some 4,200 have 4 to 6 operating rooms. The remaining 800 hospitals have between 6 and 70 operating rooms. It is reasonable to assume that at least half of the estimated 30,000 operating rooms in the U.S. are equipped to perform endoscopic surgery. In addition to hospital ORs, there exist more than 14,000 medical offices with surgery suites. Again, it is reasonable to assume that half of these office-based surgery facilities perform endoscopic procedures. Collectively, these hospitals and surgery centers, with more than 20,000 endoscopic operating rooms, form the 12,000 unit principal market for the invention.
A secondary market involves third-party endoscope repair organizations. Often these repair companies enter into contracts with hospitals and surgical centers to capitate repair expenses for endoscopes. Typically, such contracts guarantee that all the endoscopes in a facility are kept in working order. The installation of an endoscope tester at these contract facilities enables both the hospital and the repair company to quantitatively assess the endoscopes before and after repair, reducing unneeded repair costs.
Endoscopes are complex optical instruments, often containing more than 30 tiny lens components. By their very nature, these devices are prone to failure from:                Overstressing during surgery (particularly orthopedic)        Carelessness during sterilization reprocessing        Poor manufacturing design or workmanship        Wear-and-tear after many sterilization cycles.        Improper repair, especially by unauthorized repair facilitiesWith costs ranging from $2,000 to more than $20,000, it is important to efficiently repair and keep endoscopes in use as long as possible. Unfortunately, there are currently no instruments available that provide hospitals with the clinically important and 0quantitative measurements to help determine whether an endoscope is fit for surgery.        
There are three products that seek to address the need for quantitative endoscope measurements. None, however, meet the market's need for a cost-effective device that can be used in a clinical environment.
One instrument is the Lighthouse Imaging Corporation EndoBench™ tester. The advantage of the EndoBench™ tester is that it provides all of the clinically significant data to determine if an endoscope is suitable for surgery. Its cost and complexity, however, make it most suitable to a manufacturing environment.
Premise Development Corporation advertises a device called the Endotester. Like the EndoBench™ tester, this instrument performs most of the important optical measurements. Unfortunately, the Endotester requires a custom computer system and appears to be complicated to use. In addition, the Endotester is still in breadboard form and does not perform calibrated measurements, making the device of limited value in comparing test endoscopes to reference endoscopes.
DNI Nevada, Inc. manufactures the EQ-Test Endoscopy Test System. This system addresses the same market as the invention and is simple to operate. The EQ-Test does not, however, provide the needed measurements for the assessment of image quality; it only assesses the photometric characteristics of endoscopes. And, while interesting to the engineer and scientist, photometric characteristics of an endoscope are not particularly important clinically. In addition, photometry is rarely, if ever, a failure mode in endoscope usage.
The limitation of performing endoscope quality tests without a computer frame-grab system is that when viewing an endoscope image with the eye, the limiting resolution of the endoscope is fairly well matched to the limiting resolution of the eye itself. This is appropriate from an optical design point of view. It is difficult, however, from a measurement standpoint. For example, the eye at the end of a long day becomes tired and may not perform as well as in the morning. Therefore, an endoscope measurement at the end of the day may appear worse than at the beginning since it was the eye that became defective and not the endoscope.
Consequently, there is a need for a low-cost solution for testing. endoscopes and borescopes that provides the benefits of a frame-grab system and, conducts clinically significant tests beyond measurements of photometric properties, and it is a primary object to the invention to satisfy this need.
It is another object of the invention to provide apparatus and methodology for testing an endoscope or borescope by assessing the visual acuity of an observer viewing test targets through the endoscope while minimizing the impact of the, observers visual system on the results of the test.
Other objects of the invention will, in part, be obvious and others will, in part, appear hereinafter when the following detailed description is read in connection with the drawings.